U.S. patent number 5,328,215 [Application Number 07/944,373] was granted by the patent office on 1994-07-12 for pipe joint assembly.
This patent grant is currently assigned to Rovac Corporation. Invention is credited to Wilfred J. Grenier.
United States Patent |
5,328,215 |
Grenier |
July 12, 1994 |
Pipe joint assembly
Abstract
A coupling assembly for use in connecting one end of a first
tubular member to a component of a piping system includes a
receiving tubular member defining an opening adapted to receive the
first tubular member, the receiving tubular member having an inner
portion defining an inner bore dimensioned to receive the one end
and an outer portion defining an internal annular cavity
intersecting the inner bore and projecting radially outwardly
therefrom, the annular cavity comprising an annular wall portion
tapered radially inwardly and projecting longitudinally toward the
opening. Also included in the assembly is an annular seal member
and a lock ring both disposed in the annular cavity between the
first tubular member and the receiving tubular member, the lock
ring having an outer circumferential surface portion adapted to
engage said tapered wall portion and an inner circumferential
surface portion adapted to engage an external wall portion of the
first tubular member.
Inventors: |
Grenier; Wilfred J. (Rutland,
MA) |
Assignee: |
Rovac Corporation (Rochdale,
MA)
|
Family
ID: |
25481277 |
Appl.
No.: |
07/944,373 |
Filed: |
September 14, 1992 |
Current U.S.
Class: |
285/318; 285/105;
285/321; 285/322; 285/323; 285/39 |
Current CPC
Class: |
F16L
37/0925 (20130101) |
Current International
Class: |
F16L
37/00 (20060101); F16L 37/092 (20060101); F16L
039/00 (); F16L 021/06 () |
Field of
Search: |
;285/318,105,232,323,322 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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|
|
|
|
|
|
537711A1 |
|
Apr 1993 |
|
EP |
|
1-247886 |
|
Oct 1989 |
|
JP |
|
1-247889 |
|
Oct 1989 |
|
JP |
|
2-51693 |
|
Feb 1990 |
|
JP |
|
2-51694 |
|
Feb 1990 |
|
JP |
|
Primary Examiner: Bradley; P. Austin
Assistant Examiner: Knapp; Jeffrey T.
Attorney, Agent or Firm: Toupal; John E. Jarcho; Harold
G.
Claims
What is claimed is:
1. A coupling assembly comprising:
a first tubular member;
a rigid receiving tubular member defining an opening adapted to
receive said first tubular member, said receiving tubular member
having an inner portion defining an inner bore dimensioned to
receive one end of said first tubular member and an outer portion
defining an internal annular cavity intersecting said inner bore
and projecting radially outwardly therefrom, said annular cavity
comprising an annular tapered wall portion tapered radially
inwardly and projecting longitudinally toward said opening;
an annular sealing member disposed in said annular cavity and
dimensioned to be engaged between said first tubular member and
said receiving tubular member; and
a split lock ring formed from a length of spring material having a
substantially circular transverse cross-section and disposed in
said annular cavity between said annular sealing member and said
opening, said lock ring having an outer circumferential surface
portion adapted to engage said tapered wall portion and an inner
circumferential surface portion adapted to engage an external wall
portion of said first tubular member, said lock ring being adapted
to expand circumferentially into said annular cavity during
insertion of said first tubular member into said receiving tubular
member and to be compressed between said tapered wall portion and
said external wall portion in response to relative longitudinal
separating movement between said first tubular member and said
receiving tubular member, and said inner circumferential surface
portion defining circumferentially extending knife edge means for
penetrating said external wall portion so as to prevent
longitudinal movement of said first tubular member relative to said
receiving tubular member; and wherein said receiving tubular member
further defines an annular divider means projecting radially into
said cavity between said sealing member and said split lock ring,
and said tapered wall portion terminates with a radially inwardly
directed integrally formed rim defining a shoulder stop portion at
an outer end of said receiving tubular member, and said shoulder
stop portion is adapted to engage said lock ring in response to
said separating movement.
2. An assembly according to claim 1 wherein said knife edge means
is a circumferential edge formed by a circumferential groove in
said lock ring.
3. An assembly according to claim 2 wherein said groove defines one
wall terminated by said circumferential edge and oriented
transversely to said external wall portion.
4. An assembly according to claim 3 wherein said one wall is
substantially perpendicular to said external wall portion.
5. An assembly according to claim 4 wherein said groove further
defines another wall extending between said one wall and an outer
surface of said lock ring.
6. An assembly according to claim 5 wherein said another wall is
substantially perpendicular to said one wall.
7. An assembly according to claim 1 wherein said lock ring has
first and second ends normally axially displaced with said lock
ring in a relaxed condition, and said first and second ends are
forced toward axial alignment in response to compression of said
lock ring between said tapered wall portion and said external wall
portion.
8. An assembly according to claim 7 wherein said knife edge means
is a circumferential edge formed by a circumferential groove in
said lock ring.
9. An assembly according to claim 8 wherein said groove defines one
wall terminated by said circumferential edge and oriented
transversely to said external wall portion.
10. An assembly according to claim 8 wherein said split ring has an
inner diameter less than the outer diameter of said first tubular
member.
11. An assembly according to claim 1 wherein said receiving tubular
member further defines an annular transitional wall portion tapered
between said cavity and said inner bore.
12. An assembly according to claim 1 including an auxiliary ring
disposed in said annular cavity between said lock ring and said
sealing member, said auxiliary ring being engaged between an inner
surface of said cavity and said external wall portion, and wherein
an inner circumference of said auxiliary ring defines longitudinal
edges projecting substantially parallel to a longitudinal axis of
said first tubular member and adapted to penetrate the outer
surface thereof.
13. An assembly according to claim 12 wherein said auxiliary ring
is a cut ring having separated ends.
14. A coupling assembly comprising:
a first tubular member;
a receiving tubular member defining an opening adapted to receive
said first tubular member, said receiving tubular member having an
inner portion defining an inner bore dimensioned to receive one end
of said first tubular member and an outer portion defining an
internal annular cavity intersecting said inner bore and projecting
radially outwardly therefrom, said annular cavity comprising an
annular tapered wall portion tapered radially inwardly and
projecting longitudinally toward said opening;
an annular sealing member disposed in said cavity and dimensioned
to be engaged between said first tubular member and said receiving
tubular member; and
a split lock ring formed from spring material and disposed in said
annular cavity between said annular sealing member and said
opening, said lock ring having an outer circumferential surface
portion adapted to engage said tapered wall portion and an inner
circumferential surface portion adapted to engage an external wall
portion of said first tubular member, said lock ring being adapted
to expand circumferentially into said annular cavity during
insertion of said first tubular member into said receiving tubular
member and to be compressed between said tapered wall portion and
said external wall portion in response to relative longitudinal
separating movement between said first tubular member and said
receiving tubular member, and said inner circumferential surface
portion defining circumferentially extending knife edge means for
penetrating said external wall portion so as to prevent
longitudinal movement of said first tubular member relative to said
receiving tubular member; and wherein said lock ring has first and
second ends normally axially displaced with said lock ring in a
relaxed condition, and said first and second ends are forced toward
axial alignment in response to compression of said lock ring
between said tapered wall portion and said external wall
portion.
15. An assembly according to claim 14 wherein said knife edge means
is a circumferential edge formed by a circumferential groove in
said lock ring.
16. An assembly according to claim 15 wherein said groove defines
one wall terminated by said circumferential edge and oriented
transversely to said external wall portion.
17. An assembly according to claim 16 wherein said split ring has
an inner diameter less than the outer diameter of said first
tubular member.
18. An assembly according to claim 14 wherein said lock ring has a
substantially circular cross-section.
19. An assembly according to claim 18 wherein said annular cavity
includes a longitudinal ridge, and said first and second ends and
said separated ends are disposed on opposite sides of said
ridge.
20. An assembly according to claim 19 wherein said receiving member
defines an annular rib projecting radially into said annular cavity
and disposed between said auxiliary ring and said sealing
member.
21. An assembly according to claim 13 wherein said annular cavity
further comprises a cylindrical wall portion extending between said
tapered wall portion and said inner bore, and said auxiliary ring
and said sealing member are adapted for engagement between said
cylindrical wall portion and said first tubular member.
22. An assembly according to claim 21 wherein said lock ring is
dimensioned so as to prevent engagement thereof with said
cylindrical wall portion during said circumferential expansion by
said first tubular member.
23. An assembly according to claim 1 wherein said tapered wall
portion terminates with a radially inwardly directed rim forming a
shoulder stop portion at an outer end of said receiving tubular
member, and said stop portion is adapted to engage said lock ring
in response to said separating movement.
Description
BACKGROUND OF THE INVENTION
The invention relates generally to an improved pipe coupling
assembly and, more particularly, to an easily assembled and
disassembled pipe coupling assembly.
Known methods for connecting a length of metal pipe or tubing to
valves or pipe fittings such as elbows and tees include the use of
threaded connectors, soldering, compression fitting, flaring, and
welding. Non-metallic pipe, such as thermoplastic pipe, may also be
joined by adhesives.
These methods are all subject to various drawbacks. Methods calling
for the application of heat or force can be awkward and time
consuming to practice in cramped and inaccessible areas, for
example, areas in which residential plumbing is typically located.
Soldering, welding and the like require the attention of a skilled
worker using special tools to produce a good connection. Moreover,
it is often difficult and time consuming to disconnect a length of
pipe from a fitting once they have been joined, and it is often not
possible to disassemble the joint without damaging the pipe or the
fitting to such an extent that they cannot later be rejoined.
Acceptable pipe joints are more difficult to make when the pipe is
to carry a fluid under pressure. Even where threaded pipe and
threaded connectors are used, greater skill is required to produce
a strong and leakproof seal which will withstand the pressure
rating of the pipe being joined. For proper sealing under pressure,
washers or O-rings are often included in the joint. If the washer
and pipe are made of dissimilar metals, they will sometimes undergo
electrolysis in the presence of moisture in the joint or water and
chemical agents flowing through the pipe. Electrolytic action leads
to degradation of the washer, which can eventually cause the joint
to leak and loosen the locking action of lock washers.
Some of the aforementioned drawbacks are overcome by the use of
plastic pipe joined by adhesive. But plastic pipe is difficult to
connect directly to metal valve fittings without special adaptors.
Moreover, once sealed with adhesive, prior plastic pipe joints
cannot be readily undone. Disclosed in U.S. patent application Ser.
No. 07/747,290, now abandoned, is an improved coupling assembly
that alleviates many of the above noted problems. However, the
operational characteristics of the disclosed coupling are not
suitable for all applications.
The object of this invention, therefore, is to provide an improved
pipe coupling assembly that can be easily assembled and
disassembled by unskilled workers.
SUMMARY OF THE INVENTION
The invention is a coupling assembly for use in connecting one end
of a first tubular member to a component of a piping system and
including a receiving tubular member defining an opening adapted to
receive the first tubular member, the receiving tubular member
having an inner portion defining an inner bore dimensioned to
receive the one end and an outer portion defining an internal
annular cavity intersecting the inner bore and projecting radially
outwardly therefrom, the annular cavity comprising an annular
tapered wall portion tapered radially inwardly and projecting
longitudinally toward the opening. Also included in the assembly is
an annular seal member and a split lock ring both disposed in the
annular cavity between the first tubular member and the receiving
tubular member, the lock ring having an outer circumferential
surface portion adapted to engage said tapered wall portion and an
inner circumferential surface portion adapted to engage an external
wall portion of the first tubular member. The lock ring is formed
of spring material and adapted to expand circumferentially into the
annular cavity during insertion of the first tubular member into
the receiving tubular member and to be compressed between the
tapered wall portion and the external wall portion in response to
relative longitudinal separating movement between the first tubular
member and the receiving tubular member. In addition, the inner
circumferential surface portion defines a circumferentially
extending knife edge for penetrating the external wall portion so
as to prevent longitudinal movement of the first tubular member
relative to the receiving tubular member.
According to one feature of the invention, the knife edge is formed
by a circumferential groove in the lock ring. The easily formed
groove provides the desired knife edge for locking the two tubular
members.
According to other features of the invention, the groove defines
one wall terminated by the circumferential edge and oriented
substantially perpendicular to the external wall portion, and
another wall substantially perpendicular to the one wall and
extending between the one wall and an outer surface of the lock
ring. An effective knife edge is formed by the one and another
walls.
According to another feature of the invention, the lock ring has an
inner diameter less than the outer diameter of the first tubular
member, has first and second ends normally axially displaced, and
the first and second ends are forced into substantial alignment in
response to compression of the lock ring between the tapered wall
portion and the external wall portion. The spring characteristics
of the split ring facilitate its expansion into the annular cavity
and create a longitudinally directed force that restricts movement
of the first tubular member into the receiving tubular member.
According to an additional feature, the assembly includes an
auxiliary ring having separated ends and disposed in the annular
cavity between said lock ring and the sealing member, the auxiliary
ring being engaged between an inner surface of the cavity and the
external wall portion, and an inner circumference of the auxiliary
ring defining longitudinal edges projecting substantially parallel
to a longitudinal axis of the first tubular member and adapted to
penetrate the outer surface thereof. The auxiliary ring prevents
rotation of the first tubular member within the receiving tubular
member.
According to yet other features of the invention, the annular
cavity further comprises a cylindrical wall portion extending
between the tapered wall portion and the inner bore, the auxiliary
ring and the sealing member are adapted for engagement between the
cylindrical wall portion and the first tubular member, and the lock
ring is dimensioned so as to prevent engagement thereof with the
cylindrical wall portion during its circumferential expansion by
the first tubular member. This feature facilitates insertion of the
first tubular member into the receiving tubular member.
According to still another feature of the invention, the tapered
wall portion terminates with a radially inwardly directed rim
forming a shoulder stop portion at an outer end of the receiving
tubular member, and the stop portion is adapted to engage the lock
ring in response to the separating movement. The stop portion
positively retains the lock ring within the completed assembly.
The invention also encompasses a disengagement tool for use with
the above assembly and including first and second arcuately shaped
parts attached by a flexible connector and each having a
longitudinally extending inner cylindrical surface conforming to
the outer surface of the first tubular member and adapted for
engagement therewith in a juxtaposed relationship to form a
composite outer tube, the composite outer tube adapted for sliding
movement on the first tubular member and having an actuator annular
end adapted to be pushed through the opening into the annular
cavity and into forcible engagement with the lock ring so as to
cause circumferential expansion thereof. The disengagement tool
eliminates engagement between the knife edge and the first tubular
member to permit removal thereof.
DESCRIPTION OF THE DRAWINGS
These and other objects and features of the invention will become
more apparent upon a perusal of the following description taken in
conjunction with the accompanying drawings wherein:
FIG. 1 is a longitudinal cross sectional view of a coupling
assembly according to the invention;
FIG. 2 is a cross sectional view taken along lines 2--2 of FIG.
1;
FIG. 3 is a side view of a lock ring utilized in the assembly of
FIG. 1;
FIG. 4 is a cross sectional view taken along lines 4--4 in FIG.
3;
FIG. 5 is a cross sectional view taken along lines 5--5 in FIG.
3;
FIG. 6 is a side view of an auxiliary ring utilized in the assembly
of FIG. 1;
FIG. 7 is a cross sectional view taken along lines 7--7 in FIG.
6;
FIG. 8 is a cross sectional view illustrating assembly of the pipe
coupling shown in FIGS. 1;
FIG. 9 is a cross sectional view after assembly of the pipe
coupling shown in FIG. 1;
FIG. 10 is a perspective view of a disengagement tool for use in
disassembling the pipe coupling shown in FIG. 1;
FIG. 11 is a longitudinal cross sectional view of the tool shown in
FIG. 10;
FIG. 12 is a transverse cross sectional view of the tool shown in
FIG. 10;
FIG. 13 is a transverse cross sectional view showing the tool of
FIG. 10 positioned over a tube; and
FIG. 14 is a cross sectional view illustrating use of the
disengagement tool shown in FIGS. 10-13.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Illustrated in FIGS. 1 and 2 is a pipe coupling assembly 11
including an inner first tubular member 12 and an outer receiving
tubular member 13. The tubular member 12 generally will be a length
of pipe or tubing such as commonly employed for the delivery of
fluids. For the purposes of the invention no distinction is to be
made between pipe and tubing, and as understood herein both are
embraced by the word "pipe". The embracing tubular member 13 will
generally form a part of a pipe fitting, such as an elbow, tee, or
the like, or will form a part of some other component of a piping
system, such as a valve.
The receiving tubular member 13 includes an inner portion 14, an
outer portion 15 and an end portion 16 with a radially inwardly
directed rim 18 that defines a circular opening 17 and an inwardly
directed shoulder 19. Defined by the inner portion 14 of the
receiving tubular member 13 is an inner bore 21 dimensioned to
snugly receive the outer surface of the first tubular member 12.
The outer portion 15 of the receiving tubular member 13 defines an
annular cavity 22 intercepting the inner bore 21 and projecting
radially outwardly therefrom. Forming the annular cavity 22 is a
cylindrical wall portion 24 and an annular tapered wall portion 25
joining the cylindrical wall portion 24 and the shoulder 19
surrounding the opening 17. An annular gap 27 is formed between the
first tubular member 12 and the rim 17 which has a diameter larger
than the outer surface thereof. Defining an annular shoulder 28 on
the receiving tubular member 13 is a counterbore 29. An annular rib
31 on the receiving tubular member 13 projects inwardly from the
cylindrical portion 24 and separates the cavity 22 into
longitudinally separated cavity portions 32 and 33. Projecting
inwardly from the cylindrical wall portion 24 in the cavity portion
32 is a longitudinally disposed ridge 34.
The pipe coupling assembly 11 also includes a split lock ring 35
disposed in the cavity portion 32, a sealing member 36 such as a
resilient O-ring disposed in the cavity portion 33, and a split
auxiliary ring 37 disposed in the cavity portion between the lock
ring 35 and the annular rib 31.
The lock ring 35 is made from a material suitable to establish a
good spring characteristic. As shown in FIGS. 3-5, the lock ring 35
has a circular cross-section, an outer circumferential surface
portion 41 of diameter D less than the diameter of the adjacent
cylindrical wall portion 24, and an inner circumferential surface
portion 42 of diameter d less than the outer diameter of the first
tubular member 12. Cut in the inner surface portion 42 is a
circumferential groove 44 formed by one wall 43 oriented
perpendicular to an outer surface 45 of the first tubular member
12, and another wall 47 extending between the outer surface of the
ring 35 and the one wall 43 and oriented perpendicular thereto. The
another wall 47 extends from the one wall 44 toward the opening 17
in the tubular member 13; Formed by the periphery of the one wall
43 is a circumferential knife edge 48 extending parallel to the
outer surface 45 of the first tubular member 12. First and second
ends 51, 52 of the lock ring 35 straddle a split therein and, as
shown in FIG. 3, the second end 52 is axially displaced from the
first end 51 which is circumferentially aligned with the major
portion of the ring 35.
The auxiliary ring 37 also is formed from a suitable spring
material and has separated ends 54, 55 straddling a gap 56. An
outer circumference 61 of the auxiliary ring 37 engages the
cylindrical surface portion 24 of the cavity portion 32. Cut into
an inner circumference 62 are circumferentially spaced apart teeth
63 that form longitudinally disposed edges 64 oriented parallel to
the axis of the first tubular member 12. When assembled within the
cavity portion 32 of the tubular member 13, the ends 54,55 of the
auxiliary ring 37 and the ends 51, 52 of the lock ring 35 engage
opposite sides of the ridge 34 as shown in FIG. 1.
OPERATION
During assembly of the coupling 11, the first tubular member 12 is
inserted through the opening 17 in the receiving tubular member 13
until an inner end 68 of the member 12 engages the annular shoulder
28 as shown in FIG. 4. As the first tubular member 12 moves through
the annular cavity 22, its external surface engages the knife edge
inner surface 48 of the lock ring 35 expanding it outwardly into
the cavity portion 32 of the annular cavity 22. However, since the
outer diameter D of the lock ring 35 is less than that of the
cylindrical wall portion 24, inward axial movement of the first
tubular member 12 is not restricted. In addition, the auxiliary
ring 37 is compressed between the cylindrical surface portion 24
and the outer surface of the first tubular member 12 which outer
surface is scored by the longitudinal projecting edges 64. Because
of this penetration of the first tubular member 12 by the edges 64
on the compressed auxiliary ring 37, rotation of the first member
12 within the receiving member 13 is prevented. A tapered annular
transitional surface 69 between the cylindrical surface portion 24
and the inner bore 21 accommodates longitudinal migration of the
sealing member 36 so as to prevent damage thereto during insertion
of the first tubular member 12 as shown in FIG. 8.
After full insertion, the first tubular member 12 is partially
withdrawn to produce a longitudinal separation movement relative to
the receiving tubular member 13. During that movement, the lock
ring 35 is forced longitudinally outwardly in the annular cavity 22
and tightly compressed therein between the shoulder stop 19, the
tapered wall portion 25 and the outer surface of the first tubular
member 12 as shown in FIG. 9. Because of the penetration of the
outer surface of the first tubular member 12 by the knife edge 48
on the lock ring 35, further relative longitudinal movement between
the member 12 and the receiving tubular member 13 is prevented. In
addition, the second end 52 of the lock ring 35 is forced into
circumferential alignment with the first end 51 creating an axially
directed force that biases the member 12 inwardly in the member 13.
Fluid pressure within the coupling 11 exerts on the first member 12
a longitudinally outwardly directed force F that is transferred by
the tapered wall portion 25 radially inwardly on the lock ring 35.
Consequently, the knife edge 48 is driven further into the outer
surface of the first member 12 and enhancing the securement thereof
to the receiving member 13. With the parts in the relative
positions shown in FIG. 9, the O-ring 36 is engaged between the
cylindrical surface portion 24 and the outer surface of the first
tubular member 12 to create a fluid tight seal therebetween. The
annular rib 31 prevents damage of the annular sealing member 36 by
the teeth 63 on the auxiliary ring 37.
Disassembly of the coupling 11 requires the use of a disengagement
tool 71 shown in FIGS. 10-13. The disengagement tool 51 consists of
first and second identically shaped arcuate parts 72, 73,
respectively. Each of the parts 72, 73 has a longitudinally
extending inner cylindrical surface 74 conforming to the outer
surface of the first tubular member 12. One end 75 of the part 72
is connected to one end 76 of the part 73 by a flexible connection
portion 77 that permits relative pivotal movement therebetween as
shown in FIG. 12. When positioned on the outer surface of the first
tubular member 12, the parts 72, 73 form a composite tube 78 that
defines an outer actuator end 80 having an outwardly facing,
annular tapered surface 81. Extending radially outwardly from each
of the parts 72, 73 is a flange portion 82, 83, respectively.
To disassemble the coupling 11, the opposite ends 84, 85 of the
parts 72, 73, respectively, are separated as shown in FIG. 12
allowing the tool 71 to be positioned around the member 12 with the
surfaces 74 engaging the outer surface thereof. Next, the flange
portions 82, 83 of the parts 72, 73 are pushed to produce sliding
movement of the cylindrical surfaces 74 on the outer surface of the
first tubular member 12. That sliding movement is continued to move
the annular actuator end 80 of the composite tube 78 through the
annular gap 27 until the flange portions 82, 83 engage the outer
end 16 of the receiving tubular member 13. During the inward
movement of the actuator end 80, the annular tapered surface 81
engages and forces the lock ring 35 into an inward position as
shown in FIG. 14. Movement into that inner portion of the cavity 22
allows the lock ring 35 to expand circumferentially in response to
the radially outwardly directed force produced by the tapered
surface 81. The circumferential expansion eliminates engagement
between the lock ring 35 and the outer surface of the first tubular
member 12. Accordingly, the first tubular member 12 can be
withdrawn easily from the receiving tubular member 13.
Obviously, many modifications and variations of the present
invention are possible in light of the above teachings. It is to be
understood, therefore, that the invention can be practiced
otherwise than as specifically described.
* * * * *